Improved machine for drawing bolts by hydraulic pressure



UNITED STATES PATENT OFFICE.

SETH WILMARTH, OF BOSTON, MASSACHUSETTS.

IMPROVED MACHINE FOR DRAWING BOLTS BY HYDRAULIC PRESSURE.

Specification forming part of Letteis Patent No. 45,785, dated January3, 1865.

To all whom it may concern:

Ee it known that I, SETH WILMARTH, of Boston, in the county of Suffolkand State of Massachutsetts, have invented a new and useful Machine forDra-wing Bolts by Means of H ydraulic Pressuie; and I hereby declare thefollowing to be a full, clear, and exact description thereof, referencebeing had to the accompanying drawings, making part of thisspecification, in which- Figure l is a front elevation of my improvedbolt-drawing machine. Fig. 2is a horizontal section on the line .r x ofFig. l. Fig. 3 is a vertical section through a portion of the foot ofthe machine, taken in the direction of the j line y y of Fig. 2, a partot' the base also being represented in elevation. Fig. 4 is a 'sideelevation of the Lipper portion of the machine, showing where the poweris applied to operate the torce-pump.

The object of my invention is to employ a power for withdrawing bolts,85e., from ,timbers which shall perform the opera-tion in a mostexpeditious and ei'ectual manner without injury to the bolt or timber;and my invention consists in grasping the bolt by two or morewedge-shaped jaws sliding in inclined slots within a cavity formed atthe base ot`the outer cylinder ot' a hydraulic jack or lit't, whereby lam enabled to exert and apply an immense force in the most advantageousmanner, the line ot' draft being directly in the line ofthe axis ofthebolt.

To enable others skilled inthe art to understa-ud and use my invention,l will proceed to describe the manner in which l have carried it out. I

In the said drawings the base of the outer casing A ot' the hydraulicliftis enlarged so as to admit of a conical cavity, B, being formedwithin it, and inclined slots a are cut in its sides for the wedgeshaped jaws b to slide in. Thesejaws are prevented from projecting belowthe base ot the outer casing A 4by means ot' pins c, itting into groovesd made in the lower part of the backs of the jaws, and their frontsurfaces are notched or serrated to enable them to securely hold thebolt C. Eyebolts e are screwed into the heads of the jaws,

and a chain, y, passes through them and through the eye of a bolt, g, inthe side of the outer cylinder A, by which means the jaws are raised-andadjusted to tit the heads of bolts of various diameters. The base ofthis outer cylinder, when down in its normal position, rests partly onthe surface ot' the timber from which the bolt is to be drawn and partlyon the enlargement D at the foot of the inner cylinder, E, which is madehollow to contain the water or other fluid, by pressure on which theouter cylinderis elevated. The inner and outer cylinders are made to teach other truly, so that the joint between them is perfectlywater-tightwhen the pressureis applied. The enlargement D at the lowerend of the inner cylinder is bifurcated, and extends around a part ofthe base of the outer cylinder for the purpose of insuring greaterstabil ity during the operation of extracting the bolt.

The power for operating the pump t'or forcing the water into the chamberformed by the outer cylinder rising above the top otl the inner cylinderis applied at F. (See Fig. 4.)

Operation: The machine being placed with the lower surfaces ot the basesof the cylinders resting upon the timber from which the bolt is to beextracted, the jaws b are adjusted by means of the chainf, so as toembrace the projecting end ot' the bolt U, when, power being applied tothe hydraulic pump at F, an enormous pressure is exerted in elevatingthe outer cylinder A, which, as it commences to rise, tightens the graspot' the jaws b on the bolt, the grip upon the bolt being at all timesproportionate to the amount ot' resistance to be overcome.

What I claim aa; my invention, and desire to secure by Letters Patent,is-

A boltdrawing machine consisting ot' a vise or jaws for grasping thebolt, in combination.

with a hydraulic lift for withdrawing the same, operating substantiallyin the manner herein set forth.

SE TH VVILMARTH.

Witnesses:

P. E. TEscHEMAcHEE, N. W. STEARNS.

